Pharmacology · Class
Fixed-dose antiretroviral combinations !
Two, three or more antiretrovirals in one tablet. Fewer pills mean better adherence and less risk of resistance.
Updated 2026-11-01
What they are
Co-formulations of drugs from different classes that make up a complete regimen or its NRTI backbone. WHO promotes them to simplify public-health treatment; the combination of dolutegravir, lamivudine and tenofovir disoproxil (TLD) is the most widely used first-line regimen worldwide.
Mechanism of action
Each component keeps its own mechanism. The combination hits the virus at two or more steps (for example reverse transcription and integration), so a single mutation is not enough for it to escape.
Target: Several HIV targets at once (reverse transcriptase, integrase, protease)
Drugs in this class
Others in the class
- Abacavir + lamivudine
- Abacavir + dolutegravir + lamivudine
- Emtricitabine + tenofovir disoproxil
- Efavirenz + lamivudine + tenofovir disoproxil
- Efavirenz + emtricitabine + tenofovir disoproxil
- Lamivudine + zidovudine
- Bictegravir + emtricitabine + tenofovir alafenamide
Test yourself
Think of the answer, then tap the question to see it.
What is the main advantage of a fixed-dose combination?
It simplifies treatment and improves adherence, which reduces virological failure and resistance.
Which components make up the TLD regimen?
Tenofovir disoproxil, lamivudine and dolutegravir: two NRTIs and an integrase inhibitor.
Why does combining drugs from several classes prevent resistance?
The virus would need mutations against each mechanism at the same time, which is very unlikely when suppression is complete.
Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.
Sources: ATCDDD - ATC/DDD Index (WHO Collaborating Centre for Drug Statistics Methodology, 2026); WHO recommends dolutegravir as preferred HIV treatment option in all populations (World Health Organization, 2019); eEML - Electronic Essential Medicines List (World Health Organization, 2025).
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Representative model, for educational purposes only.